Bulbless expansion valve with integrated bypass check valve

ABSTRACT

An expansion valve including a valve body having an inlet, an outlet, a main flow passage extending from inlet to outlet, and a metering orifice in the at least one main flow passage. A power element controls movement of a valve member relative to the metering orifice to control flow of operating fluid passing across the metering orifice when the valve is operating in a forward flow expansion mode. The valve body includes an internal bypass flow passage that bypasses the metering orifice, and a bypass check valve is arranged internally of the valve body in the bypass flow passage. The bypass check valve is configured to open at least partially in response to operating fluid flowing in a reverse flow bypass mode in which activation of the bypass check valve opens the bypass flow passage to permit operating fluid to bypass the metering orifice in the reverse bypass mode.

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.63/196,827 filed Jun. 4, 2021, which is hereby incorporated herein byreference in its entirety.

TECHNICAL FIELD

The present invention relates generally to expansion valves, and moreparticularly to a bulbless style expansion valve with integrated bypasscheck valve.

BACKGROUND

An expansion valve, also referred to as a thermal expansion valve (TEV),is a common component of a vapor-compression system that is used forregulating refrigerant flow. During cooling, the TEV receives liquidrefrigerant from a condenser, throttles the refrigerant flow with avalve member of the TEV, and allows expansion of the refrigerant into avapor-liquid mixture. The expanded two-phase refrigerant leaves the TEVand enters an indoor heat exchanger that serves as an evaporator whichallows the refrigerant to absorb heat, transition to vapor, and becomesuperheated. The superheated vapor leaves the evaporator through asuction line and enters a compressor where the refrigerant gas iscompressed. The hot pressurized refrigerant gas flows back to thecondenser which serves as a heat exchanger that allows the refrigerantto dissipate heat and condense into a liquid, which is then circulatedback through the TEV.

To control the amount of expanded refrigerant released into theevaporator, the TEV uses a power element that is in thermalcommunication with the suction line by way of a sensing bulb. The chargein the power element reacts to the pressure and temperature changeswhereby a diaphragm expands or retracts the valve member to therebyincrease flow when high superheat is sensed and decrease flow when lowsuperheat is sensed.

SUMMARY

In refrigerant systems, bulbless-style TEVs are commonly used. Abulbless-style TEV generally includes a valve body containing two mainpassages that are connected in parallel to different parts of therefrigerant circuit. Such refrigerant systems also can be used as a heatpump when run in reverse. In a reverse flow heat pump mode, therefrigerant leaves the compressor as a superheated vapor and the indoorheat exchanger extracts heat from the refrigerant into the indoor space.As such, the indoor heat exchanger serves as the condenser in a heatingmode, whereby the cooled refrigerant condenses into a liquid. A problemwith such TEVs, however, is that in the reverse flow direction, theliquid refrigerant flow would be restrictive against the valve member ofthe TEV. As such, an external bypass line with a non-return valve isused to bypass the TEV, and a second heat-mode TEV is used to expand theliquid refrigerant into a vapor-liquid mixture that flows to the outdoorunit which now serves as the evaporator. This external bypass lineinvolves costly piping and an external check valve that consumes space.

At least one aspect of the present disclosure provides a unique thermalexpansion valve with an internal bypass passage and integrated checkvalve within the bypass passage that enable the operating fluid tobypass the flow restrictive metering orifice in the main flow passagewhen the system is operated in a reverse flow mode. Such an integratedcheck valve is configured to seal the bypass passage in a forward flowexpansion mode, and is configured to automatically activate to open thebypass passage in response to reverse flow. By integrating the reverseflow check valve into the expansion valve, the reverse flow restrictionis minimized, thereby enabling use of the system in both bypass andexpansion modes. Without the integrated check valve, an external bypassline around the expansion valve would be required, which would involvecostly piping and an external check valve that consumes space. As such,the unique thermal expansion valve according to the present disclosurecan provide a compact and efficient unit which may be suitable for usein automotive applications.

In exemplary embodiments, the bypass arrangement provides a hermeticseal in which all leak paths are contained within the valve and/orwithin the fluid circuit of the system to prevent a direct leak toambient external environment.

In exemplary embodiments, the bypass arrangement is at least partiallyin-line with the main flow passage such that at least a portion of themain passage downstream of the metering orifice is shared with thebypass passage. Such an arrangement reduces the possibility of externalleakage and reduces the size of the bulbless valve body.

In exemplary embodiments, the valve body is configured such that thecheck valve is inserted in-line with the main flow passage. Such in-linepositioning of the check valve also helps to restrict leakage externallyof the valve body, since any such leakage would flow into the main flowpath and/or the fluid circuit of the system.

According to an aspect of the present disclosure, a bulbless-styleexpansion valve includes: a valve body having a first inlet, a firstoutlet, a first main flow passage extending from the first inlet to thefirst outlet, a metering orifice in the first main flow passage betweenthe first inlet and the first outlet, a second inlet, a second outlet,and a second main flow passage extending from the second inlet to thesecond outlet, the second main flow passage being separate from thefirst main flow passage; a valve member movable in the valve bodyrelative to the metering orifice to control flow of operating fluidpassing through the first main flow passage and across the meteringorifice as operating fluid flows from the first inlet to the firstoutlet when the valve is operating in a forward flow expansion mode; apower element operatively coupled to the valve member and configured tocontrol movement of the valve member at least partially in response tochanges in temperature and pressure of operating fluid passing throughthe second main flow passage from the second inlet to the second outletwhen the valve is operating in the forward flow expansion mode; a bypassflow passage extending internally through the valve body and bypassingthe metering orifice; and a bypass check valve arranged internally ofthe valve body in the bypass flow passage, the bypass check valve beingconfigured to activate at least partially in response to operating fluidflowing in a reverse flow bypass mode in which activation of the bypasscheck valve opens the bypass flow passage to permit operating fluid tobypass the metering orifice in the reverse flow bypass mode.

According to another aspect, a thermal expansion valve includes: a valvebody having at least one inlet, at least one outlet, at least one mainflow passage extending from the at least one inlet to the at least oneoutlet, and a metering orifice in the at least one main flow passagebetween the at least one inlet and the at least one outlet; a valvemember movable in the valve body relative to the metering orifice tocontrol flow of operating fluid passing through the at least one mainflow passage and across the metering orifice as operating fluid flowsfrom the at least one inlet to the first at least one when the valve isoperating in a forward flow expansion mode; a power element comprisingan actuator operatively coupled to the valve member and configured tocontrol movement of the valve member; a bypass flow passage extendinginternally through the valve body and bypassing the metering orifice;and a bypass check valve arranged internally of the valve body in thebypass flow passage, the bypass check valve being configured to activateat least partially in response to operating fluid flowing in a reverseflow bypass mode in which activation of the bypass check valve opens thebypass flow passage to permit operating fluid to bypass the meteringorifice in the reverse flow bypass mode.

According to another aspect, a bulbless valve includes: a valve bodyhaving a suction passage through which fluid flows from a heat exchangerto a compressor in a forward flow mode and from the compressor to theheat exchanger when the valve is operating in a reverse flow mode, and,the valve further defining a first opening and a second openingconnected by a passage, and an orifice between the first opening and thesecond opening; a valve member driven by a power element to control theflow of fluid through the orifice; a check valve positioned in thepassage and configured such that when the check valve is in an openposition, fluid can flow from the second opening to the first opening,and when the valve is in the closed position fluid is blocked from thepassage.

The following description and the annexed drawings set forth certainillustrative embodiments of the invention. These embodiments areindicative, however, of but a few of the various ways in which theprinciples of the invention may be employed. Other objects, advantagesand novel features according to aspects of the invention will becomeapparent from the following detailed description when considered inconjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The annexed drawings, which are not necessarily to scale, show variousaspects according to the present disclosure.

FIG. 1 is a cross-sectional side view of an exemplary thermal expansionvalve (TEV) according to the present disclosure, which is incorporatedinto a system, and which is shown operating in a forward flow expansionmode with metering functionality while the system is cooling.

FIG. 2 is another cross-sectional side view of the TEV in FIG. 1 , whichis shown operating in a reverse flow mode with bypass functionalitywhile the system is heating.

FIG. 3 is an enlarged view of the cross-section shown in FIG. 2 , but inthe forward flow expansion mode according to FIG. 1 .

FIG. 4A is a perspective view of the TEV in FIGS. 1-3 , and FIG. 4B isthe opposite perspective view of the TEV.

FIG. 5A is an enlarged quarter section view of the TEV in FIGS. 1-4Bshowing the forward flow expansion mode.

FIG. 5B is an enlarged quarter section view of the TEV in FIGS. 1-4Bshowing the reverse flow bypass mode.

FIG. 6 is a cross-sectional side view of another exemplary TEV accordingto the present disclosure.

FIG. 7 is a cross-sectional side view of another exemplary TEV accordingto the present disclosure.

FIG. 8 is a cross-sectional side view of another exemplary TEV accordingto the present disclosure.

DETAILED DESCRIPTION

The principles and aspects according to the present disclosure haveparticular application to bulbless-style thermal expansion valves (TEVs)for use in heat pump applications, and thus will be described belowchiefly in this context. It is understood, however, that the principlesand aspects according to the present disclosure may be applicable toother TEVs for heat pump systems, such as residential, commercial, orautomotive air conditioning or refrigeration systems, for example.

FIGS. 1-5B show an exemplary bulbless-style expansion valve withintegrated check valve 20 (also referred to as a thermal expansion valveor TEV 20). FIG. 1 shows a schematic diagram of a refrigerant system 10incorporating the exemplary TEV 20 in which the system 10 is running ina forward flow cooling mode and a first cross-sectional view of the TEV20 is shown metering and expanding operating fluid through the valve.FIGS. 3 and 5A are enlarged views from different cross-sections of theTEV 20 still showing operation in the forward flow expansion mode, asdescribed in further detail below. FIG. 2 shows a schematic diagram ofthe system 10 operating in a reverse flow heat pump mode and secondcross-sectional view of the TEV 20 is shown bypassing operating fluid.FIG. 5B is an enlarged view from a different cross-section of the TEV 20showing the bypass functionality when operating in the reverse flowbypass mode, as described in further detail below.

Referring initially to FIG. 1 , the exemplary TEV 20 generally includesa valve body 22 having a first inlet 24, a first outlet 26, and a firstmain flow passage 28 extending from the first inlet 24 to the firstoutlet 26. In the illustrated embodiment, the TEV 20 is arranged betweena first heat exchanger 12 and a second heat exchanger 14 of the system10. The TEV first inlet 24 is fluidly connected to an outlet of thefirst heat exchanger 12 to receive operating fluid in the forward flowexpansion mode, and the TEV first outlet 26 is fluidly connected to aninlet of the second heat exchanger 14. When the system 10 is operatingto cool with the TEV 20 in the forward flow expansion mode, the secondheat exchanger 14 serves as an evaporator contained within a space to becooled (e.g., indoors), and the first heat exchanger 12 serves as acondenser that is located outside of the cooled space (e.g., outdoors).As is conventional in a refrigerant system, the system 10 also includesa compressor 16 positioned between the outlet of the second heatexchanger 14 (evaporator) and the inlet of the first heat exchanger 12(condenser). In the forward flow mode, the operating fluid, such as asuitable refrigerant, circulates through the system 10 and is compressedby the compressor 16 which raises the temperature and pressure of therefrigerant. The then hot pressurized refrigerant gas flows through thefirst heat exchanger 12 (condenser) to allow the refrigerant todissipate heat. The first heat exchanger 12 lowers the refrigeranttemperature such that the refrigerant condenses into a liquid whichpasses to the first inlet 24 of the TEV 20.

In the forward flow expansion mode, the TEV 20 is configured as arefrigerant modulating valve that controls expansion of the liquidrefrigerant received from the first heat exchanger 12 (condenser),whereby some of the refrigerant evaporates and transforms into atwo-phase vapor-liquid mixture. To provide such expansion, the TEV 20includes a metering orifice 30 arranged in the first main flow passage28 which forms a flow restriction in cooperation with a valve member 31that creates a region of high pressure in an inlet portion 28 a of themain flow passage 28 between the first inlet 24 and the metering orifice30, and a region of low pressure in an outlet portion 28 b of the mainflow passage 28 between the metering orifice 30 and the first outlet 26.The refrigerant expands and transforms to the two-phase mixture as itmoves across the metering orifice from the high-pressure region to thelow-pressure region.

The cold liquid-vapor refrigerant passes through the first outlet 26downstream of the TEV 20 into circuits of the second heat exchanger 14(evaporator), thus absorbing heat from inside the space that is to becooled. The second heat exchanger 14 (evaporator) could be located, forexample, in the plenum of a forced air residential or commercial airconditioning system through which air is blown for cooling the interiorof the residence or building. In automotive applications, the secondheat exchanger 14 (evaporator) typically is located in the dashboardinside the vehicle cabin. In the forward expansion mode, the coldliquid-vapor mixture absorbs heat from the second heat exchanger 14(evaporator) thereby returning the refrigerant to a gaseous vapor state.The refrigerant vapor is then cycled back to the compressor 16 through asuction line of the system 10.

In the illustrated embodiment, the valve body 22 of the TEV 20 forms atleast a portion of the fluid (suction) line between the second heatexchanger 14 and the compressor 16. As shown, the valve body 22 includesa second inlet 32 fluidly connected to the outlet of the second heatexchanger 14 (evaporator), and a second outlet 34 fluidly connected tothe inlet of the compressor 16. The valve body 22 forms a second mainflow passage 36 extending from the second inlet 32 to the second outlet34, in which this second main flow passage 36 is fluidly separated fromthe first main flow passage 28 in the valve body 22. To prevent leakageof operating fluid, the TEV 20 is sealed in the system 10, such as byproviding suitable connections at the respective inlets 24, 32 andoutlets 26, 34. For example, the fluid lines of the system 10 mayinclude conduit or piping that is welded, brazed, or otherwise sealed tothe inlets/outlets of the valve body 22.

To control the amount of expansion across the metering orifice 30, thevalve member 31 is movable in the valve body 22 relative to the meteringorifice 30. The metering orifice 30 and/or valve member 31 may have anysuitable structure(s) for opening, closing, or modulating flow throughthe first main flow passage 28 to control the amount of expansion by theTEV 20. In the illustrated embodiment, the metering orifice 30 is formedas an adjustable flow restrictive opening in the annular region betweena valve seat 38 in the first main passage 28 and a poppet or pin portionof the valve member 28 that serves as an engagement portion of the valvemember 28 that is operative to engage the valve seat 38 and close theTEV 20. The metering orifice 30 and thus flow through the first mainpassage 28 can be closed when the valve member 31 engages the valve seat38.

The TEV 20 also includes a power element 40 that serves as an actuatoroperatively coupled to the valve member 31 for controlling movement ofthe valve member 31. The power element 40 is operatively mounted to thevalve body 22, and include a casing 42 that forms an enclosure whichcontains a flexible diaphragm 44. The diaphragm 44 may be a thin metalsheet that fluidly separates the casing enclosure into a first (upper)chamber 46 and a second (lower) chamber 48. The first chamber 46 ischarged with a charge fluid, such as a refrigerant, and the secondchamber 48 is in communication with the operating fluid flowing throughthe second main flow passage 36. A dome 47 also may be included which isin fluid communication with the first chamber 46 to also contain thecharge fluid and help to reduce the responsiveness of the valve. Aballast material (not shown) may be contained within the dome 47 tofurther reduce reactivity and enable better control of the valve. Thechanges in temperature and pressure of the operating fluid (gaseousvapor) flowing through the second main flow passage 36 is communicatedto a (lower) side of the diaphragm 44 via the second (lower) chamber 48which acts against the pressure on the opposite (upper) side of thediaphragm from the charge fluid in the first (upper) chamber 46. The TEV20 may further include an adjustment mechanism 49, such as aspring-biased adjuster including a spring 49 a and pin 49 b foradjusting spring force, whereby the spring force urges the valve member31 toward closed and combines with fluid pressure at the underside ofthe diaphragm 44 for counteracting the pressure from the first (upper)chamber 46 and thereby setting a desired control setpoint of the TEV 20.As the temperature and pressure of the operating fluid (vapor) flowingthrough the second main passage 36 changes, the charge in the powerelement 40 reacts to these pressure and temperature changes, exertingforce on the diaphragm 44 and causing the diaphragm 44 to flex. This, inturn, exerts force on the valve member 31 causing the valve member 31 tomove relative to the metering orifice 30. As such, the power element 40responds to sensing high temperature flow through the second mainpassage 36 by adjusting the valve member 31 to increase flow through thefirst main passage 28, and responds to sensing low temperature flowthrough the second main passage 36 by adjusting the valve member 31 todecrease flow through the first main passage 28. In this manner, thepower element 40 is configured to control movement of the valve member31 at least partially in response to changes in temperature and pressureof operating fluid passing through the second main flow passage 36.

Referring now to FIG. 2 , the exemplary vapor-compression system 10 alsocan be used as a heat pump when run in reverse. As shown in theillustrated embodiment, the system 10 may include a four-way reversingvalve 18 that is configured to control forward or reverse flow throughthe system 10. In a reverse flow heating mode, the first heat exchanger12 serves as an evaporator which draws heat into the refrigerant andtransforms it into a superheated vapor which is passed to the compressor16. The refrigerant leaves the compressor 16 as a superheated vapor andthe second heat exchanger 14 (now serving as a condenser) extracts heatfrom the refrigerant into the space to be heated (e.g., indoors). Theheat extracted from the refrigerant condenses the superheated vapor intoa liquid, which exits the outlet of the second heat exchanger 14 andflows to the TEV 20.

As is apparent in the illustrated embodiment, in the reverse flowdirection, the liquid refrigerant flow into the first outlet 26 wouldforce the valve member 31 toward the valve seat 38 and undesirablyrestrict flow. Accordingly, the exemplary TEV 20 provides a uniquebypass arrangement including an internal bypass passage 50 that extendsthrough the valve body 22 and bypasses the flow restriction at themetering orifice 30 in the reverse flow mode. The unique bypassarrangement also includes an integrated check valve 52 arranged withinthe bypass passage 50 that is configured to open the bypass passage 50when the system is operated in the reverse flow heat pump mode. Such anintegrated check valve 52 is configured to seal the bypass passage 50 inthe forward flow expansion mode (as shown in FIGS. 3 and 5A) so thatflow passes through the first main flow passage 28 and across themetering orifice 30, and is configured to automatically activate to openthe bypass passage 50 in response to reverse flow (as shown in FIGS. 2and 5B). As such, integrating the reverse flow check valve 52 into theTEV 20 enables use of the TEV 20 in the system in both bypass andexpansion modes. To expand the refrigerant in the system heating mode,another TEV between the TEV 20 and the first heat exchanger 12(evaporator) may be provided, which may be the same as TEV 20 butarranged in reverse to provide expansion in the system reverse flowmode.

The bypass arrangement including the configuration of the bypass passage50 and/or the configuration of the check valve 52 may have any suitabledesign as may be desired for the particular application. In exemplaryembodiments, the bypass arrangement provides a hermetic seal in whichall leak paths are contained to within the valve body 22 and/or to theconnections with the system piping to prevent a direct leak to ambientexternal environment. For example, as best shown in FIGS. 4A and 4B, thebypass passage 50 shares at least a first connection port 54 with thefirst outlet 26, and shares at least a second connection port 56 withthe first inlet 24. The first connection port 54 is connected withconduit or piping that is connected to the second heat exchanger 14, andthe second connection port 56 is connected with conduit or piping thatis connected to the first heat exchanger 12. As shown in FIGS. 3 and 5B,the bypass passage 50 may include an upstream portion 50 a that sharesthe connection portion 54 with the first outlet 26, but the upstreamportion 50 a has a separate flow path than the outlet portion 28 b ofthe first main flow passage 28 and thus routes around the meteringorifice 30 where the valve member 31 creates a flow restriction with thevalve seat 38. Also as shown in FIGS. 3 and 5B, the bypass passage 50may include an opening 58, such as a through-passage, that fluidlyconnects the upstream portion 50 a to the inlet portion 28 a of thefirst main passage 28, such that the inlet portion 28 a is shared withthe bypass passage 50 and thus the inlet portion 28 a also serves as adownstream portion 50 b of the bypass flow passage 50 in the reverseflow direction. Such sharing of flow paths helps to reduce the size ofthe valve body 22 and reduces the possibility of leakage to the externalenvironment. In the illustrated embodiment, the opening 58 is opened orclosed with the check valve 52. When operating in the forward expansionmode, the check valve 52 closes the opening 58, thus closing the portion50 a of the bypass flow passage 50 and forcing flow across the meteringorifice 30. Also as best shown in FIGS. 3 and 4A, the check valve 52 maybe arranged completely internally within the valve body 22, and may beinserted via an internal bore 60 having an insertion opening 62 that isfluidly connected with the connection port 56. As such, any leakage ofthe check valve 52 would leak internally within the system piping,instead of externally to ambient environment.

Referring particularly to FIG. 3 , in the illustrated embodiment, thecheck valve 52 is configured as a plunger-style check valve 52,including a stationary plug 64 arranged in the internal bore 60, and aplunger 66 that is movable within the stationary plug 64. The plug 64includes at least one seal 67 that restricts leakage out of the bore 60,and the plunger 66 includes at least one seal 68 that engages a valveseat 70 upstream of the opening 58 to open or close the bypass passage50. The plunger-style check valve 52 is configured such that motion ofthe plunger 66 is controlled by the cooperation between a bore 72 in theplug 64 and a stem 73 of the plunger 66. The fit between the bore 72 andstem 73 permits linear motion of the plunger 66 with a hard stop in thebore 72 when fully retracted, and the valve seat 70 provides a hard stopfor the plunger 66 in the extended position. When the check valve 52 isactivated (in the retracted position) for reverse flow, refrigerant canflow into the connection port 54 of the valve body 22, into the upstreamportion 50 a of the bypass flow passage 50, through the opening 58, andinto the downstream portion 50 b of the bypass passage which also is theinlet portion 28 a of the main flow passage 28, and then out of thefirst inlet 24 of the valve body 22. When the check valve 52 is in theclosed position (as shown in FIG. 3 ), refrigerant flow is blockedthrough the opening 58. A pressure differential created by thecompressor 16 in the system facilitates the advancing and retracting ofthe plunger 66. It is understood that other types of check valves couldbe used in place of the plunger-style check valve 52, such as a ball orcup style check valve, which may include a spring-biased ball. In someembodiments, the plunger-style check valve 52 may include a spring tohold the plunger 66 in the extended or retracted position. The in-lineorientation of the check valve 52 allows the check valve to be hermeticto the system and decreases diameter of the adjusting gland and/orspring cavity of the adjustment mechanism 49. It is understood that thebypass arrangement, including location of the check valve 52 and/orconfiguration of the bypass flow passage 50, may be different in otherembodiments, and may not include a hermetic seal internally of thesystem piping, as may be desirable for cost or other considerations.

Referring to FIGS. 6-8 , other exemplary embodiments of TEVs 120, 220,320 are shown. The TEVs 120, 220, 320 are substantially the same as theabove-referenced TEV 20, and consequently the same reference numeralsbut respectively in the 100, 200 and 300-series are used to denotestructures corresponding to similar structures in the TEVs. In addition,the foregoing description of the TEV 20 is equally applicable to theTEVs 120, 220, 320, except as noted below. In addition, it is understoodthat aspects of the TEVs 20, 120, 220, 320 may be substituted for oneanother or used in conjunction with one another where applicable.

The TEVs 120, 220, 320 have essentially the same arrangement of the flowpassages and valving for expansion of the refrigerant in the forwardflow expansion mode, but have different arrangements of their respectivebypass passages and the locations of their respective bypass checkvalves. As such, similarly to the TEV 20, the TEVs 120, 220, 320respectively include a valve body 122, 222, 322 having a first inlet124, 224, 344; a first outlet 126, 226, 326; a first main flow passage128, 228, 328 extending from the first inlet to the first outlet, ametering orifice 130, 230, (hidden in FIG. 8 ) in the first main flowpassage between the first inlet and the first outlet, a valve member131, 231, 331 movable in the valve body 122, 222, 322 relative to themetering orifice to control flow of operating fluid passing through thefirst main flow passage and across the metering orifice as therespective TEV is operating in a forward flow expansion mode to receiveliquid from a condenser and to pass two-phase liquid to an evaporator.The TEVs 120, 220, 320 also respectively include a second inlet 132,232, (not shown in FIG. 8 ); a second outlet 134, 234, (not shown inFIG. 8 ); and a second main flow passage 136, 236, 336 extending fromthe second inlet to the second outlet, in which the second main flowpassage forms at least a portion of a suction line in the forwardexpansion mode which is separate from the first main flow passage. Alsosimilarly to the TEV 20, the TEVs 120, 220, 320 respectively include apower element 140, 240, 340 which comprise an actuator, such as aflexible diaphragm 144, 244, 344, that is operatively coupled to thevalve member 131, 231, 331. The power element 140, 240, 340 isconfigured to control movement of the valve member at least partially inresponse to changes in temperature and pressure of operating fluidpassing through the second main flow passage 136, 236, 336 from thesecond inlet to the second outlet when the valve is operating in theforward flow expansion mode. In addition, similarly to TEV 20, the TEVs120, 220, 320 respectively include a bypass flow passage 150, 250, 350extending internally through the valve body 122, 222, 322 and bypassingthe metering orifice 130, 230, (not shown in FIG. 8 ); and furtherinclude a check valve 152, 252, 352 arranged internally of the valvebody in the bypass flow passage 150, 250, 350, in which the check valveis configured to activate at least partially in response to operatingfluid flowing in a reverse flow bypass mode whereby the check valve 152,252, 352 opens the bypass flow passage 150, 250, 350 to permit operatingfluid to bypass the metering orifice in the reverse flow bypass mode.

Referring particularly to FIG. 6 , instead of having the check valvearranged horizontally through a bore recessed in the inlet connectionport as is the case with the TEV 20, the TEV 120 has its check valve 152arranged vertically to be inserted through a bore 160 having an opening162 in the second main flow passage 136. In the illustration, the checkvalve 152 is shown in its closed state to close the bypass flow passage150. The bypass arrangement in the illustrated embodiment utilizes theconnection port 154 at the first outlet 126 and the outlet portion 128 bof the first main passage 128 is a shared passage with the upstreamportion 150 a of the bypass passage 150. In the reverse flow bypassmode, the bypass flow passes across the poppet portion of the valvemember 131 to act against the plunger 166 of the check valve 152 toactivate it to open. When the check valve 152 is opened, the bypass flowbypasses the metering orifice 130 and passes to the downstream portion150 b of the bypass passage 150. As shown, the downstream portion 150 bof the bypass passage is a shared passage with the inlet portion 128 aof the first main passage 128 and also shares the same connection port156. In this manner, with the shared passages, the TEV 120 minimizessize. The TEV 120 also is hermetic to the system since any leakage pastthe check valve 152 is contained within the system. However, suchleakage would permit leakage from the suction line of the second mainpassage 136 to the liquid line of the first main passage 128.

Referring to FIG. 7 , the TEV 220 has its check valve 252 arrangedvertically to be inserted through a bore 260 having an opening 262 inthe bottom of the valve body 222. The bore 260 is plugged with asuitable plug 275 to prevent loss of refrigerant from the valve body222. The check valve 252 in this arrangement includes a central passage276 through plunger 266 that is plugged with a plug 277 in a closedstate, and which permits communication through orifices 278 in thestationary plug 264 in the open state. In the illustration, the checkvalve 252 is shown in its open state to open the bypass flow passage250. The bypass arrangement in the illustrated embodiment utilizes theconnection port 254 at the first outlet 226 and an upstream portion 250a of the bypass passage 250 that branches off from the outlet portion228 b of the first main passage 228. When the check valve 252 is opened,the bypass flow bypasses the metering orifice 230 and passes to thedownstream portion 250 b of the bypass passage 250, which is a sharedpassage with the inlet portion 228 a of the first main passage 228 andalso shares the same connection port 256. In this manner, with theshared passages, the TEV 220 minimizes size. The introduction of theplug 275 into the bore 260 provides an additional possible leak path,but otherwise any leakage past the check valve 252 is contained towithin the system. The passage 260 and plug 275 could be omitted if thediameter of the adjustment mechanism 249 were increased to allow theinsertion of the check valve.

Referring to FIG. 8 , the TEV 320 has its check valve 352 insertedthrough opening 362 into a bore 360 arranged at an angle through asidewall of the valve body 322. In the illustration, the check valve 352is shown in its closed state to close the bypass flow passage 350. Thebypass arrangement in the illustrated embodiment utilizes the connectionport at the first outlet (hidden from view) and the outlet portion ofthe first main passage 328 is a shared passage with the upstream portionof the bypass passage 350. In the reverse flow bypass mode, the bypassflow passes across the poppet portion of the valve member 331 to actagainst the plunger 366 of the check valve 352 to activate it to open.When the check valve 352 is opened, the bypass flow bypasses themetering orifice (hidden from view) and passes to the downstream portion350 b of the bypass passage 350. This downstream portion 350 b of thebypass passage 350 opens into the inlet portion of the first mainpassage 328 and permits bypass flow to exit through the first inlet 324.The TEV 320 is not hermetic to the system since any leakage past thecheck valve 352 can escape to the external environment.

While exemplary forms of a TEV 20, 120, 220, 320 have been describedabove, it understood that alternative configurations also could beemployed. For example, although the TEVs have been shown and describedabove as bulbless-style expansion valves, the TEV also could be anon-bulbless style TEV, such as one that uses a sensing bulb andcapillary tube to sense the temperature in the suction line, as would beunderstood by those having ordinary skill in the art.

According to an aspect, a bulbless-style expansion valve includes: avalve body having a first inlet, a first outlet, a first main flowpassage extending from the first inlet to the first outlet, a meteringorifice in the first main flow passage between the first inlet and thefirst outlet, a second inlet, a second outlet, and a second main flowpassage extending from the second inlet to the second outlet, the secondmain flow passage being separate from the first main flow passage; avalve member movable in the valve body relative to the metering orificeto control flow of operating fluid passing through the first main flowpassage and across the metering orifice as operating fluid flows fromthe first inlet to the first outlet when the valve is operating in aforward flow expansion mode; a power element operatively coupled to thevalve member and configured to control movement of the valve member atleast partially in response to changes in temperature and pressure ofoperating fluid passing through the second main flow passage from thesecond inlet to the second outlet when the valve is operating in theforward flow expansion mode; a bypass flow passage extending internallythrough the valve body and bypassing the metering orifice; and a bypasscheck valve arranged internally of the valve body in the bypass flowpassage, the bypass check valve being configured to activate at leastpartially in response to operating fluid flowing in a reverse flowbypass mode in which activation of the bypass check valve opens thebypass flow passage to permit operating fluid to bypass the meteringorifice in the reverse flow bypass mode.

Exemplary embodiments may include one or more of the followingadditional features, separately or in any combination.

In exemplary embodiment(s), the check valve and bypass flow passage arearranged to provide hermetic sealing in which any leakage past the checkvalve does not escape to an external environment outside of the valveand/or system in which the valve is incorporated.

In exemplary embodiment(s), the bypass check valve is at least partiallyarranged in-line with the first main flow passage.

In exemplary embodiment(s), the first outlet of the first main flowpassage and an inlet of the bypass flow passage share a common externalconnection port of the valve body which is configured to connect aconduit of a system incorporating the valve.

In exemplary embodiment(s), the first inlet of the first main flowpassage and an outlet of the bypass flow passage share a common externalconnection port of the valve body which is configured to connect aconduit of a system incorporating the valve.

In exemplary embodiment(s), the first main flow passage includes anupstream portion this is upstream of the metering orifice when the valveis operating in the forward flow expansion mode.

In exemplary embodiment(s), the bypass flow passage includes adownstream portion that is downstream of a check valve seat that thebypass check valve engages when closed.

In exemplary embodiment(s), at least a portion of the upstream portionof the first main flow passage and at least a portion of the downstreamportion of the bypass flow passage are a commonly shared passage in thevalve body.

In exemplary embodiment(s), the first main flow passage includes adownstream portion this is downstream of the metering orifice when thevalve is operating in the forward flow expansion mode.

In exemplary embodiment(s), the bypass flow passage includes an upstreamportion that is upstream of a check valve seat that the bypass checkvalve engages when closed.

In exemplary embodiment(s), at least a portion of the downstream portionof the first main flow passage and at least a portion of the upstreamportion of the bypass flow passage are a commonly shared passage in thevalve body.

In exemplary embodiment(s), the bypass flow passage includes a firstupstream portion that is shared with a portion of the downstream portionof the first main flow passage, and wherein the bypass flow passageincludes a second upstream portion that branches off from the first mainflow passage and extends internally within the valve body to the checkvalve seat.

In exemplary embodiment(s), the bypass check valve is inserted into avertical bore having an opening in a bottom of the valve body, whereinat least part of the bore is plugged.

In exemplary embodiment(s), the bypass check valve is inserted into avertical bore having an opening in the second main flow passage.

In exemplary embodiment(s), the bypass check valve is inserted into aninclined bore having an opening in a sidewall of the valve body.

In exemplary embodiment(s), the bypass check valve is inserted into abore having an opening in a recessed portion of the common externalconnection port of the first inlet of the first main flow passage andthe outlet of the bypass flow passage.

In exemplary embodiment(s), the first main flow passage includes adownstream portion this is downstream of the metering orifice when thevalve is operating in the forward flow expansion mode, wherein thebypass flow passage includes an upstream portion that is upstream of acheck valve seat that the bypass check valve engages when closed, andwherein the upstream portion of the bypass flow passage is fluidlyseparated from the downstream portion of the first main flow passage.

In exemplary embodiment(s), the bypass flow passage includes athrough-opening in the valve body that is downstream of the check valveseat, the through-opening being configured to fluidly connect theupstream portion of the bypass flow passage to a downstream portion ofthe bypass flow passage when the bypass check valve is activated toopen.

In exemplary embodiment(s), the downstream portion of the bypass flowpassage is commonly shared with an upstream portion of the first mainflow passage that is upstream of the metering orifice when the valve isoperating in the forward flow expansion mode.

In exemplary embodiment(s), the bypass check valve is inserted into abore having an opening in a recessed portion of a common externalconnection port of the first inlet of the first main flow passage and anoutlet of the bypass flow passage.

In exemplary embodiment(s), the check valve comprises a stationary plugand a plunger that is movable relative to the plug.

In exemplary embodiment(s), the power element comprises a casing and aflexible diaphragm at least partially within the casing, the flexiblediaphragm being operatively coupled to the valve member and beingconfigured to flex at least partially in response to changes intemperature and pressure of operating fluid passing through the secondmain flow passage when the valve is operating in the forward flowexpansion mode.

In exemplary embodiment(s), the metering orifice is formed as anadjustable flow restrictive opening in an annular region between a valveseat in the first main flow passage and an engagement portion of thevalve member.

According to another aspect, a thermal expansion valve for a system,includes: a valve body having at least one inlet, at least one outlet,at least one main flow passage extending from the at least one inlet tothe at least one outlet, and a metering orifice in the at least one mainflow passage between the at least one inlet and the at least one outlet;a valve member movable in the valve body relative to the meteringorifice to control flow of operating fluid passing through the at leastone main flow passage and across the metering orifice as operating fluidflows from the at least one inlet to the first at least one when thevalve is operating in a forward flow expansion mode; a power elementcomprising an actuator operatively coupled to the valve member andconfigured to control movement of the valve member; a bypass flowpassage extending internally through the valve body and bypassing themetering orifice; and a bypass check valve arranged internally of thevalve body in the bypass flow passage, the bypass check valve beingconfigured to activate at least partially in response to operating fluidflowing in a reverse flow bypass mode in which activation of the bypasscheck valve opens the bypass flow passage to permit operating fluid tobypass the metering orifice in the reverse flow bypass mode; wherein thevalve body includes an external inlet port configured to fluidly connectto a conduit of the system, and an external outlet port configured tofluidly connect to another conduit of the system, and wherein the bypasscheck valve is inserted into a bore in the valve body having an openingat the external inlet port or at the external outlet port.

According to another aspect, a bulbless valve includes: a valve bodyhaving a suction passage through which fluid flows from a heat exchangerto a compressor in a forward flow mode and from the compressor to theheat exchanger when the valve is operating in a reverse flow mode, and,the valve further defining a first opening and a second openingconnected by a passage, and an orifice between the first opening and thesecond opening; a valve member driven by a power element to control theflow of fluid through the orifice; a check valve positioned in thepassage and configured such that when the check valve is in an openposition, fluid can flow from the second opening to the first opening,and when the valve is in the closed position fluid is blocked from thepassage.

According to another aspect, a system includes: a first heat exchanger,a second heat exchanger, and the valve according to any of the foregoingfeatures, which is located between first and second heat exchangers,wherein the valve is configured meter fluid flow from the first heatexchanger to the second heat exchanger in the forward flow expansionmode, wherein the valve is configured to bypass flow from the secondheat exchanger to the first heat exchanger in a reverse flow bypassmode, and wherein the system does not have an external bypass line thatbypasses the valve in the reverse flow bypass mode.

As used herein, an “operative connection,” or a connection by whichentities are “operatively connected,” is one in which the entities areconnected in such a way that the entities may perform as intended. Anoperative connection may be a direct connection or an indirectconnection in which an intermediate entity or entities cooperate orotherwise are part of the connection or are in between the operativelyconnected entities. An operative connection or coupling may include theentities being integral and unitary with each other.

It is to be understood that terms such as “top,” “bottom,” “upper,”“lower,” “left,” “right,” “front,” “rear,” “forward,” “rearward,” andthe like as used herein may refer to an arbitrary frame of reference,rather than to the ordinary gravitational frame of reference.

The phrase “and/or” should be understood to mean “either or both” of theelements so conjoined, i.e., elements that are conjunctively present insome cases and disjunctively present in other cases. Other elements mayoptionally be present other than the elements specifically identified bythe “and/or” clause, whether related or unrelated to those elementsspecifically identified unless clearly indicated to the contrary. Thus,as a non-limiting example, a reference to “A and/or B,” when used inconjunction with open-ended language such as “comprising” can refer, inone embodiment, to A without B (optionally including elements other thanB); in another embodiment, to B without A (optionally including elementsother than A); in yet another embodiment, to both A and B (optionallyincluding other elements); etc.

The word “or” should be understood to have the same meaning as “and/or”as defined above. For example, when separating items in a list, “or” or“and/or” shall be interpreted as being inclusive, i.e., the inclusion ofat least one, but also including more than one, of a number or list ofelements, and, optionally, additional unlisted items. Only terms clearlyindicated to the contrary, such as “only one of” or “exactly one of,”may refer to the inclusion of exactly one element of a number or list ofelements. In general, the term “or” as used herein shall only beinterpreted as indicating exclusive alternatives (i.e. “one or the otherbut not both”) when preceded by terms of exclusivity, such as “either,”“one of,” “only one of,” or “exactly one of.”

Although the principles, embodiments and operation of the presentinvention have been described in detail herein, this is not to beconstrued as being limited to the particular illustrative formsdisclosed. They will thus become apparent to those skilled in the artthat various modifications of the embodiments herein can be made withoutdeparting from the spirit or scope of the invention. In particularregard to the various functions performed by the above describedelements (components, assemblies, devices, compositions, etc.), theterms (including a reference to a “means”) used to describe suchelements are intended to correspond, unless otherwise indicated, to anyelement which performs the specified function of the described element(i.e., that is functionally equivalent), even though not structurallyequivalent to the disclosed structure which performs the function in theherein illustrated exemplary embodiment or embodiments of the invention.In addition, while a particular feature of the invention may have beendescribed above with respect to only one or more of several illustratedembodiments, such feature may be combined with one or more otherfeatures of the other embodiments, as may be desired and advantageousfor any given or particular application.

1. A bulbless-style expansion valve, comprising: a valve body having afirst inlet, a first outlet, a first main flow passage extending fromthe first inlet to the first outlet, a metering orifice in the firstmain flow passage between the first inlet and the first outlet, a secondinlet, a second outlet, and a second main flow passage extending fromthe second inlet to the second outlet, the second main flow passagebeing separate from the first main flow passage; a valve member movablein the valve body relative to the metering orifice to control flow ofoperating fluid passing through the first main flow passage and acrossthe metering orifice as operating fluid flows from the first inlet tothe first outlet when the valve is operating in a forward flow expansionmode; a power element operatively coupled to the valve member andconfigured to control movement of the valve member at least partially inresponse to changes in temperature and pressure of operating fluidpassing through the second main flow passage from the second inlet tothe second outlet when the valve is operating in the forward flowexpansion mode; a bypass flow passage extending internally through thevalve body and bypassing the metering orifice; and a bypass check valvearranged internally of the valve body in the bypass flow passage, thebypass check valve being configured to activate at least partially inresponse to operating fluid flowing in a reverse flow bypass mode inwhich activation of the bypass check valve opens the bypass flow passageto permit operating fluid to bypass the metering orifice in the reverseflow bypass mode; wherein the first outlet of the first main flowpassage and an inlet of the bypass flow passage share a common externalconnection port of the valve body which is configured to connect aconduit of a system incorporating the valve.
 2. The expansion valveaccording to claim 1, wherein the check valve and bypass flow passageare arranged to provide hermetic sealing in which any leakage past thecheck valve does not escape to an external environment outside of thevalve and/or system in which the valve is incorporated.
 3. The expansionvalve according to claim 1, wherein the bypass check valve is at leastpartially arranged in-line with the first main flow passage. 4.(canceled)
 5. The expansion valve according to claim 1, wherein thefirst inlet of the first main flow passage and an outlet of the bypassflow passage share a second common external connection port of the valvebody which is configured to connect a second conduit of the systemincorporating the valve.
 6. The expansion valve according to claim 1,wherein the first main flow passage includes an upstream portion that isupstream of the metering orifice when the valve is operating in theforward flow expansion mode, wherein the bypass flow passage includes adownstream portion that is downstream of a check valve seat that thebypass check valve engages when closed, and wherein at least a portionof the upstream portion of the first main flow passage and at least aportion of the downstream portion of the bypass flow passage are acommonly shared passage in the valve body.
 7. The expansion valveaccording to claim 1, wherein the first main flow passage includes adownstream portion this that is downstream of the metering orifice whenthe valve is operating in the forward flow expansion mode, wherein thebypass flow passage includes an upstream portion that is upstream of acheck valve seat that the bypass check valve engages when closed, andwherein at least a portion of the downstream portion of the first mainflow passage and at least a portion of the upstream portion of thebypass flow passage are a commonly shared passage in the valve body. 8.The expansion valve according to claim 7, wherein the bypass flowpassage includes a first upstream portion that is shared with a portionof the downstream portion of the first main flow passage, and whereinthe bypass flow passage includes a second upstream portion that branchesoff from the first main flow passage and extends internally within thevalve body to the check valve seat.
 9. The expansion valve according toclaim 8, wherein the bypass check valve is inserted into a vertical borehaving an opening in a bottom of the valve body, wherein at least partof the bore is plugged.
 10. The expansion valve according to claim 1,wherein the bypass check valve is inserted into a vertical bore havingan opening in the second main flow passage.
 11. The expansion valveaccording to claim 1, wherein the bypass check valve is inserted into aninclined bore having an opening in a sidewall of the valve body.
 12. Theexpansion valve according to claim 5, wherein the bypass check valve isinserted into a bore having an opening in a recessed portion of thesecond common external connection port of the first inlet of the firstmain flow passage and the outlet of the bypass flow passage.
 13. Theexpansion valve according to claim 1, wherein the first main flowpassage includes a downstream portion this is downstream of the meteringorifice when the valve is operating in the forward flow expansion mode,wherein the bypass flow passage includes an upstream portion that isupstream of a check valve seat that the bypass check valve engages whenclosed, and wherein the upstream portion of the bypass flow passage isfluidly separated from the downstream portion of the first main flowpassage.
 14. The expansion valve according to claim 13, wherein thebypass flow passage includes a through-opening in the valve body that isdownstream of the check valve seat, the through-opening being configuredto fluidly connect the upstream portion of the bypass flow passage to adownstream portion of the bypass flow passage when the bypass checkvalve is activated to open. 15-16. (canceled)
 17. The expansion valveaccording to claim 1, wherein: the power element comprises a casing anda flexible diaphragm at least partially within the casing, the flexiblediaphragm being operatively coupled to the valve member and beingconfigured to flex at least partially in response to changes intemperature and pressure of operating fluid passing through the secondmain flow passage when the valve is operating in the forward flowexpansion mode; and/or wherein the metering orifice is formed as anadjustable flow restrictive opening in an annular region between a valveseat in the first main flow passage and an engagement portion of thevalve member; and/or wherein the check valve comprises a stationary plugand a plunger that is movable relative to the plug. 18-21. (canceled)22. A bulbless-style expansion valve, comprising: a valve body having afirst inlet, a first outlet, a first main flow passage extending fromthe first inlet to the first outlet, a metering orifice in the firstmain flow passage between the first inlet and the first outlet, a secondinlet, a second outlet, and a second main flow passage extending fromthe second inlet to the second outlet, the second main flow passagebeing separate from the first main flow passage; a valve member movablein the valve body relative to the metering orifice to control flow ofoperating fluid passing through the first main flow passage and acrossthe metering orifice as operating fluid flows from the first inlet tothe first outlet when the valve is operating in a forward flow expansionmode; a power element operatively coupled to the valve member andconfigured to control movement of the valve member at least partially inresponse to changes in temperature and pressure of operating fluidpassing through the second main flow passage from the second inlet tothe second outlet when the valve is operating in the forward flowexpansion mode; a bypass flow passage extending internally through thevalve body and bypassing the metering orifice; and a bypass check valvearranged internally of the valve body in the bypass flow passage, thebypass check valve being configured to activate at least partially inresponse to operating fluid flowing in a reverse flow bypass mode inwhich activation of the bypass check valve opens the bypass flow passageto permit operating fluid to bypass the metering orifice in the reverseflow bypass mode; wherein the first inlet of the first main flow passageand an outlet of the bypass flow passage share a common externalconnection port of the valve body which is configured to connect aconduit of a system incorporating the valve.
 23. The expansion valveaccording to claim 22, wherein the check valve and bypass flow passageare arranged to provide hermetic sealing in which any leakage past thecheck valve does not escape to an external environment outside of thevalve and/or system in which the valve is incorporated.
 24. Theexpansion valve according to claim 22, wherein the bypass check valve isat least partially arranged in-line with the first main flow passage.25. The expansion valve according to claim 22, wherein the first mainflow passage includes an upstream portion this is upstream of themetering orifice when the valve is operating in the forward flowexpansion mode, wherein the bypass flow passage includes a downstreamportion that is downstream of a check valve seat that the bypass checkvalve engages when closed, and wherein at least a portion of theupstream portion of the first main flow passage and at least a portionof the downstream portion of the bypass flow passage are a commonlyshared passage in the valve body.
 26. The expansion valve according toclaim 22, wherein the bypass check valve is inserted into a verticalbore having an opening in a bottom of the valve body, wherein at leastpart of the bore is plugged; or wherein the bypass check valve isinserted into a vertical bore having an opening in the second main flowpassage; or wherein the bypass check valve is inserted into an inclinedbore having an opening in a sidewall of the valve body; or wherein thebypass check valve is inserted into a bore having an opening in arecessed portion of the common external connection port of the firstinlet of the first main flow passage and the outlet of the bypass flowpassage.
 27. The expansion valve according to claim 22, wherein thefirst main flow passage includes a downstream portion this is downstreamof the metering orifice when the valve is operating in the forward flowexpansion mode, wherein the bypass flow passage includes an upstreamportion that is upstream of a check valve seat that the bypass checkvalve engages when closed, and wherein the upstream portion of thebypass flow passage is fluidly separated from the downstream portion ofthe first main flow passage.